d) It is taller than any free standing structure in the US so is a symbol of Canadian Greatness and North American Superiority at a time the US is trying to be great again but in reality are becoming an even bigger embarrassment. Boom.

I'd go with (a), having watched the CN Tower while it was under construction, including by helicopter.

One note: My recollection is that as a federal Crown corporation (that's Canadian lingo for being owned by a federal, provincial or territorial government) at the time, subsequently privatized, CN was exempt from municipal government approvals in building the CN Tower and CN didn't tell the government they were building it until after they started construction, at least in terms of a hole in the ground.